A new operating system would be the most difficult undertaking for Google and some say the most unlikely product. "Building an OS is the dumbest thing they could do," said Ken Dulaney, an analyst at Gartner. That's because even though Google has deep pockets, it doesn't have the required experience. "I would say cellular telephone code is probably the hardest code to write per line of code for anything," he said.

In addition, introducing a new OS to the market would only exacerbate the problem that Google faces, which is a mobile market full of un-interoperable software. Google already vocally complains about how challenging it is to have to tweak software for the scores of handsets in the market, and then convince operators to load the software on the phones before they're sold.

Google has more to gain by introducing software that can run on the most devices possible, said Chris Hazelton, an IDC analyst. Google's success in the PC world is based on attracting a huge number of searches, and then charging very small amounts for advertising. "Their success is in scale," said Hazelton. To replicate that in the mobile environment, Google will want to attract the most users possible. "The best way to penetrate the market is not one device," Hazelton said.

Google would be better to offer a suite of services and applications that users can download no matter what phone they're using. The search giant can best do that by partnering with operators that will load the software onto phones before they're sold. Such partnerships, however, have been difficult to come by for Google in the U.S. where the operators view Google as a threat. The operators want to offer their own search capabilities to users so that they can profit from related advertising revenue.

But the time may be ripe for a truce. "I think what's been happening is the iPhone is causing high-end subscribers to move away from Verizon and that's hurting them," said Delaney. The Wall Street Journal this week reported that Google is in discussions with Verizon, Sprint Nextel and T-Mobile about selling handsets based on a new platform that includes various Google services as well as tools for developers to build new applications. The platform will become available in mid-2008, the Journal said. Verizon had no comment on the reported discussions.

At the same time, Google may be frustrated enough with its attempts to get into the mobile market that it may be willing to negotiate an advertising revenue-sharing agreement that the operators can live with.

The stakes are high for Google. With over 2 billion mobile subscribers on the planet, mobile is the next frontier for online advertising. So far, none of the online search giants has established itself as the clear winner in mobile. "It's an open market. There is no dominant player," said Hazelton. Yahoo, AOL and Microsoft have also been aggressively rolling out services aimed at attracting mobile users who they can then advertise to.

Even if Google does manage to sign a deal with an operator, it still faces the technical challenge of trying to develop software that can work on any phone -- a problem that all mobile software developers face. One possibility could be using Java, which runs on most current phones, said Delaney. He thinks it would be a good idea for Google to partner with Sun, which last year bought SavaJe, a struggling mobile Java operating system developer. "If they're smart, they'd go to Sun and say, 'look, we both want to beat up on Microsoft,'" Delaney said. Google could build a user interface on top of the SavaJe OS and offer an open-development environment to developers, he said.

"Java would allow Google applications to run on a wide variety of devices," Hazelton agreed. "It could be a way to reach scale."

For now, however, the market will just have to keep guessing. Some news reports say that Google plans an announcement in a couple of weeks, but the search giant isn't commenting on the subject.